The Ethics Committee hasn’t formally said it will launch an investigation into Franken, unlike a public announcement members made on restarting the investigation into Sen. Bob Menendez (D-N.J.) after his bribery and corruption trial resulted in a hung jury.

“I am asking that an ethics investigation be undertaken, and I will gladly cooperate,” Franken said in a statement released Thursday.

A probe into Franken would mark a rare example of the panel digging into behavior that occurred before a member joined the Senate.

Leeann Tweeden, a radio anchor for Los Angeles’s KABC, wrote on Thursday that during a 2006 USO tour in the Middle East Franken crafted a skit for the two that involved a kiss. She said Franken pressured her into practicing the routine and then aggressively kissed her despite her objections.

She also revealed a photo that showed Franken groping her breasts while she slept on a military plane.

The Constitution gives Congress the ability to punish its own members for “disorderly behavior, and, with the concurrence of two-thirds, expel a member."

And the chamber has given the panel the power to investigate matters that reflect upon the Senate, break the law or violate the Senate’s rules, regulations or Code of Conduct.

Senators and former staffers argue the 2006 incident would fall under the committee’s jurisdiction, even though Franken wasn’t a senator, or running for the Senate, when it took place.

“I think the Ethics Committee has broad jurisdiction,” he added. “The Ethics Committee’s responsible for maintaining the integrity of the institution so I think there’s no real restrictions on what they can look at. There are a lot of integrity of the institution issues, so I think it’s appropriate.”

He added that the committee has a “broad responsibility … [in] dealing with the integrity of the institution.”

Robert Walker, the former chief counsel and staff director of the Senate Ethics Committee, noted that the committee has previously left the door open to investigating allegations that occurred before a lawmaker joined Congress.

“Does it happen? Well, it's rare that the committee might even look preliminarily at such conduct … [But] the committee can do it, it's within the committee's discretion,” he said.

But, it noted, in dismissing the complaint it was choosing not to “exercise its jurisdiction over the matter at this time.” It reserved “the right to reopen an investigation should new allegations or evidence be brought to our attention.”

If the committee decided it did not have jurisdiction, or didn't want to risk a challenge to its jurisdiction, it could ask the Senate to pass a resolution specifically giving it authority to investigate Franken or establish a separate committee.

"I believe that they should pass a resolution to amend the jurisdiction of the committee to ensure that it has the jurisdiction to proceed," said Wilson Abney, another former staff director and chief counsel of the Ethics Committee.

Some have wondered whether the panel could look into other facets of Franken’s life. The senator has written about and discussed his own drug use in the 1970s.

But Walker predicted a Senate investigation would be focused on Tweeden’s allegation.

“I am almost certain that the committee will focus on the matter at hand and any allegations related to the matter at hand,” he said.

The Senate Ethics Committee last recommended a senator be expelled over allegations of sexual harassment or assault in 1995, against Sen. Bob Packwood (R-Ore.).

The Washington Post reported in November 1992 that 10 women alleged Packwood made unwanted sexual advances toward them. The report kicked off a nearly three-year investigation and ended with Packwood’s resignation.

The Senate Ethics Committee also said in 2011 that there was “substantial and credible evidence” that then-Sen. John Ensign (R-Nev.) broke the law when he tried to cover up an affair with a political aide. He ultimately resigned.

A review doesn’t guarantee a senator will have to resign, or even face punishment. The committee reviewed 63 allegations in 2016, according to an annual report released by the panel earlier this year.

Five of those allegations were given preliminary inquiries, while 43 were dismissed because of a lack of jurisdiction or because the actions didn’t violate Senate rules. Another 14 were dismissed because of insufficient evidence.

Of the five cases given inquiries, none resulted in the committee issuing public or private letters of admonition or disciplinary sanctions.

Most of the committee’s work during its preliminary inquiry of allegations against Franken would happen behind closed doors, with staffers and senators working to determine if there is enough evidence to go to the “adjudicatory phase.”

“The committee would have to determine that there was clear and convincing evidence of misconduct, which is a lower standard of proof than 'beyond a reasonable doubt,' ” Walker said.

If the committee decided a violation has occurred, it could take a series of actions, including sending a letter of admonition, recommending the full Senate reprimand, censure or even expel Franken.

But conservatives are crying foul over senators kicking Franken’s case to the ethics committee, arguing that he should have to immediately resign after senators called on Roy Moore to step down from the Alabama Senate race.

“The talk of a forthcoming Senate Ethics Committee probe is nothing but smoke and mirrors by his fellow members in the Senate who now have an admitted sexual predator in their midst. In so doing, these Senators are allowing a known pervert to remain in office until their so-called ‘investigation,' ” L. Brent Bozell, the chairman of ForAmerica, said in a statement.

“This is a far cry from Republican calls for Roy Moore to step away from his campaign, or their threats to refuse him a Senate seat altogether. This is a way for Democrats to kick the can down the road, to pretend that they’re standing foursquare against harassment while actually winking and nodding at their friends,” he said.